Impacts to the Sewer System from Disposal of Rags and Wipes

Massachusetts Water Resources Authority

Impacts to the Sewer System from Disposal of Rags and Wipes

Presentation to the Wastewater Advisory CommitteeCarolyn Fiore, MWRA Toxics Reduction and Control

February 7, 2014

Braintree- Weymouth Pump Station

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Braintree- Weymouth Pump Station

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Storm Summary – February 27, 2013

• Rain Gauge @ Chelsea OCC: 1.79 inches• Staff began choking BWPS at 6:20 pm on February 27 due to high

flows entering the facility.• Elevation in wet well reached a “high high” causing the facility to

briefly isolate.• South Main Pump Station - recorded maximum average hourly

flow of 349 MG• Smelt Brook overflowed from 9:22 pm until 1:30 am.• Numerous rags were removed from the pump wet well and influent

grinders.

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Braintree-Weymouth Pump Station Impacts

• Excessive number or rags entering the system has been associated with clogging of grinders and pumps.

Short Term Response• Cleaned wet well, pumps and screens

Short-Term Reponses at BWPS

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Short-Term Reponses at BWPS

Short Term Response• Installed temporary screens

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Short-Term Reponses at BWPS

Short Term Response• Installed new grinder

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Short-Term Reponses at BWPS

Short Term Response• Installed quick disconnects

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Short-Term Reponses at BWPS

Short Term Response• Bypass pumping and buried lines

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Long-Term Responses at BWPS

Long-Term Response• Perform Hydraulic and Equipment Evaluations• Alternative Evaluations include:

New pumps to reduce rag accumulation and clogging Alternative Grinder Technologies Potential to install mechanically cleaned bar screens

Including washer compacter Conveyors to remove debris

Alternative Pumping Strategies To reduce sediment and rag accumulation

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TRAC Responses

• Reviewed TRAC Database to develop a list of potential source sites

• Developed a list of facilities to be inspected based on the nature of the rags indentified at the site.

• Staff inspected numerous facilities throughout the target area.

• Contacted municipalities to determine which town may have performed sewer maintenance prior to the event.

• Inspected septage sites and reviewed manifests for the facilities• Sent rag samples to laboratory (Altran) for forensic review

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TRAC Permitted Sites

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Septage Facility

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ALTRAN Forensic Analysis of Six Rags

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Summary of ALTRAN findings

• Rag samples collected from BWPS, a septage receiving site and 2 upstream manholes

• The common contaminant for these samples, excluding the expected sewage products, is a petroleum –based oil formulation resembling light machine oil.

• Rags appear to be consistent 18 inch multiples in length, polyester, and appear to have been torn off of a round roll of cloth.

• No specific manufacturer or distributor could be identified, but if we find a suspected source, we now have a contaminant fingerprint to match.

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Ubiquitous Nature of the Problem

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Outreach and Education

MWRA has begun outreach regarding proper disposal of wipes and other materials.

• MWRA school education program: 2014 Essay, Poster and Video Contest

• Web-site Update with What not to Flush pageMWRA is considering:

• Billboard Messages• Outreach to Senior Community Centers/Developments• Social Media such as YouTube, Industry Facebook pages

and Twitter feeds

• Links to Town Web-sites• Coordinate an information television news piece

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MWRA.COM Website Updated

• http://www.mwra.com/03sewer/html/toiletnottrashcan.html

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Summary

• Equipment and operation changes at the BWPS

• TRAC Inspection and Follow-up

• Outreach /Public Education Development

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